Trunk Supporting Exoskeleton and Method of Use

ABSTRACT

An exoskeleton ( 100 ) includes two torque generators ( 116, 118 ), two thigh links ( 104,106 ), and a supporting trunk ( 112 ) rotatably coupled to the thigh links ( 104, 106 ). When a wearer bends forward in the sagittal plane such that the supporting trunk ( 112 ) extends beyond a predetermined angle A with respect to vertical, at least one of the torque generators ( 116, 118 ) imposes a resisting torque between the supporting trunk ( 112 ) and a corresponding thigh link ( 104, 106 ), thus imposing a force onto a wearer&#39;s trunk and thighs to aid in supporting the wearer in a bent position. The exoskeleton ( 100 ) may include an active or passive means ( 116, 134 ) for actuating the torque generators ( 116, 118 ). When the supporting trunk ( 112 ) does not extend beyond the predetermined angle A, the torque generators ( 116, 118 ) do not impose resisting torques between the supporting trunk ( 112 ) and the thigh links ( 104, 106 ) during the entire range of motion of the thigh links ( 104, 106 ), thus enabling a wearer to walk, run, and sit without constraint while in a substantially upright position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of U.S. patent applicationSer. No. 14/480,549, filed Sep. 8, 2014, issued as U.S. Pat. No.9,022,956 on May 5, 2015, which is a continuation-in-part of U.S. patentapplication Ser. No. 14/125,117, filed Dec. 11, 2013, which claimspriority to PCT application PCT/US12/41891, filed Jun. 11, 2012, whichclaims the benefit of U.S. patent application 61/495,484, filed Jun. 10,2011. These applications are incorporated by reference along with allother references cited in this application.

BACKGROUND OF THE INVENTION

The present invention pertains to the art of support devices for thehuman spine, more particularly to a trunk supporting exoskeletonconfigured to reduce the bending moment on a person's back during aforward bend.

In general, back support devices that are configured to assist a personin bending, lifting, or standing upright, or any combination of these,are known in the art. For example, see U.S. Pat. Nos. 6,436,065,5,951,591, 5,176,622, and 7,744,552. U.S. Pat. Nos. 1,409,326 and4,829,989 describe devices where moment is created during a bend tocounteract the moments from a person's trunk gravity weight. Thesesystems utilize a passive, spring resistance to create a torque betweenthe wearer's torso and legs. By creating a restorative moment at thehip, the probability of injury of the L5/S1 area of the spine is greatlyreduced. Once the angle between torso and leg reaches a predeterminedangle during stooping, squatting, or walking, the devices provideresistance; however, none of the devices differentiates between walkingand bending or sitting and bending. This means the user cannot walkcomfortably using these passive devices since the user's legs must pushagainst the devices during walking. Similarly, the user cannot sitcomfortably using these passive devices since the user's legs must pushagainst the devices during sitting. This is uncomfortable and hazardous,preventing the user from moving around unrestricted, and is the mostimportant reason to avoid the use of these systems in various industrialsettings. Unlike the aforementioned devices, the technology describedhere differentiates between walking and bending and between sitting andbending. Even though the relative angle between the user's trunk and aswinging thigh is similar to each other in both cases of bending andwalking (or bending and sitting), we have discovered a means by whichthey can be distinguished using minimal sensing and hardware.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to a trunk supporting exoskeletonconfigured to reduce the muscle forces in a wearer's back during forwardlumbar flexion. In general, the exoskeleton includes first and secondthigh links configured to couple to a wearer's thighs, and a supportingtrunk configured to be coupled to a wearer's trunk. The supporting trunkis rotatably coupled to the thigh links to allow flexion and extensionof the thigh links with respect to the supporting trunk. First andsecond opposing torque generators selectively create torque between thesupporting trunk and respective thigh links.

In operation, when a wearer bends forward in the sagittal plane suchthat a predetermined portion of the supporting trunk deviates or extendsbeyond a predetermined angle with respect to vertical, at least one ofthe torque generators imposes a resisting torque between the supportingtrunk and a corresponding thigh link. This causes the supporting trunkto impose a force onto a wearer's trunk, and the thigh links to imposeforces onto the wearer's respective thighs, thereby helping to supportthe wearer while in the bent position. In a first embodiment, theexoskeleton includes a passive means for actuating the torquegenerators. More specifically, when a predetermined portion of theexoskeleton extends past the predetermined angle with respect tovertical, a resilient pendulum comes into contact with an engagementbracket, causing a resisting torque between the supporting trunk and arespective thigh link. In another embodiment, the exoskeleton includesan active means for actuating the torque generators, such as hydraulicmotors, pneumatic motors, and electric motors.

The exoskeleton may include a signal processor including a controller,which produces a control signal to drive torque generators as a functionof a set of input signals received by the signal processor. The inputsignals may be generated by one or more sensors incorporated into theexoskeleton, such as a velocity sensor, an accelerometer, a forcesensor, or an angle sensor.

Importantly, when the supporting trunk does not extend beyond thepredetermined angle with respect to vertical, the torque generators donot impose resisting torques between the supporting trunk and the thighlinks during the entire range of wearer motion of the thigh links. Thus,a wearer is able to walk, run, and sit without any constraint while thewearer is in a substantially upright position.

In an implementation, a trunk supporting exoskeleton configured to beworn by a person to reduce the muscle forces in the wearer's back duringforward lumbar flexion, the exoskeleton includes: a supporting trunkconfigured to contact a wearer's trunk; and two thigh links configuredto couple to a wearer's thighs. The thigh links are rotatably coupled tothe supporting trunk in a manner that allows for flexion and extensionof thigh links relative to the supporting trunk along the human hipaxes. There are two torque generators coupled to the supporting trunkand the thigh links. When the wearer bends forward in the sagittalplane, the torque generators impose a resisting torque between thesupporting trunk and the thigh links, causing the supporting trunk toimpose a force against a wearer's trunk and the thigh links to impose aforce onto wearer's thighs.

In various implementations of the exoskeleton, at least one of the firstand second torque generators includes: an upper bracket configured to becoupled to the supporting trunk; and a lower bracket configured to becoupled to one of the first and second thigh links and rotatably coupledto the upper bracket. A resilient pendulum is rotatably coupled to theupper bracket. An engagement bracket is coupled to the lower bracket.When a predetermined portion of the upper bracket extends beyond apredetermined angle from vertical, the resilient pendulum comes intocontact with the engagement bracket, causing a resisting torque betweenthe upper bracket and the lower bracket. When the predetermined portionof the upper bracket does not extend beyond a predetermined angle fromvertical, the resilient pendulum is not in contact with the engagementbracket, and does not impose resisting torque between the upper bracketand the lower bracket.

The supporting trunk can include: a human interface configured to becoupled to a wearer's trunk; and a frame configured to be coupled to thehuman interface, where the frame is rotatably coupled to the first andsecond thigh links and allows for extension and flexion of therespective first and second thigh links relative to the supportingtrunk. The human interface can include a back panel configured tointerface with a wearer's back and a pair of shoulder straps configuredto be coupled to the back panel. The human interface can include a backpanel configured to interface with a wearer's back and a pair ofshoulder straps configured to be coupled to the back panel and theframe.

The upper bracket can be manufactured as a part of the supporting trunk.The lower bracket can be manufactured as a part of the thigh link. Thethigh link is adjustable for various lengths. The engagement bracket canbe manufactured as a part of the lower bracket. The upper bracket can bemanufactured as a part of the frame.

The frame can include a waist frame positioned behind the wearerapproximately around the wearer's waist area where the first and secondthigh links are rotatably coupled to the waist frame allowing forextension and flexion of the respective first and second thigh linksrelative to the waist frame. The frame can include a spine framepositioned behind the wearer and coupled to the waist frame. The framecan include a spine frame positioned behind the wearer and rotatablycoupled to the waist frame allowing for side-to-side motion of the spineframe relative to the waist frame. The spine frame can be adjustable inits length. The frame is adjustable to accommodate wearers of varioussizes.

The frame can include a waist frame substantially parallel with theperson's hip line and a spine frame substantially parallel with theperson's spine where the waist frame and the spine frame rotate relativeto each other. The frame can include at least one resilient element thatresists the rotation of the spine frame relative to the waist frame. Theresilient element can include an element or combination of elementsselected from a group consisting of gas spring, air spring, leaf spring,torsional spring, compression spring, linear spring and tensile spring.

The thigh link can further include a rotary joint allowing for rotationof the thigh link relative to the lower bracket. The resilient pendulumis rotatably coupled to the upper bracket where the rotating pointlocation of the resilient pendulum relative to the upper bracket isadjustable. A holding block can be rotatably coupled to the upperbracket and the resilient pendulum is secured to the holding block. Amass can be coupled to the resilient pendulum and its location relativeto the resilient pendulum can be adjusted to produce various naturaloscillation frequencies.

The resilient element includes an element or combination of elementsselected from a group consisting of gas spring, air spring, leaf spring,torsional spring, compression spring, linear spring and tensile spring.The torque generator can further include a locking system to prevent therotational motion of the resilient pendulum relative to the upperbracket.

The locking system, among other things, can include a cover bracketcoupled to the upper bracket and a moving bracket capable of movingrelative to the cover bracket. When the moving bracket is in itsunlocked position, it will not prevent the resilient pendulum fromrotating relative to the upper bracket. When the moving bracket is inits locked position, the moving bracket prevents the resilient pendulumfrom rotating relative to the upper bracket.

The moving bracket, among other components, can include a protrusionwhere when the moving bracket is in its first position, the protrusionwill not prevent the motion of resilient pendulum with respect to themoving bracket. When the moving bracket is in its second position, theprotrusion will interfere the rotation of the resilient pendulum andprevent the motion of resilient pendulum with respect to the movingbracket.

In an implementation, a trunk supporting exoskeleton configured to beworn by a person to reduce the muscle forces in the wearer's back duringforward lumbar flexion, the exoskeleton includes: a supporting trunkconfigured to support a wearer's chest; and first and second thigh linksconfigured to couple to a wearer's thighs. Each of the first and secondthigh links is rotatably coupled to the supporting trunk in a mannerthat allows for flexion and extension of respective first and secondthigh links relative to the supporting trunk. An antimoving support isconfigured to couple the person and the trunk supporting exoskeleton ina manner such that it impedes the trunk supporting exoskeleton frommoving upwardly toward the person's shoulder when the person is bending.There are first and second torque generators. Each of the first andsecond torque generators is configured to generate torque between therespective first and second thigh links and the supporting trunk. When awearer bends forward in the sagittal plane such that a predeterminedportion of the supporting trunk extends beyond a predetermined anglefrom vertical, at least one of the first or second torque generatorsimposes a resisting torque between the supporting trunk and at least oneof the first and second thigh links. This causes the supporting trunk toimpose a force against a wearer's trunk and at least one of the firstand second thigh links to impose a force onto a wearer's thigh.

The antimoving support can be a belt configured to couple the person hiparea and to couple the supporting trunk at locations close to therotation points of thigh links relative to supporting trunk in a mannersuch that forward rotation of the supporting trunk from a vertical linedoes not cause substantial motion for the seat harness. The antimovingsupport can be a seat harness configured to contact the person's buttockarea and to couple the supporting trunk at locations close to therotation points of thigh links relative to supporting trunk in a mannersuch that forward rotation of the supporting trunk from a vertical linedoes not cause substantial motion for the seat harness.

The antimoving support can include at least a thigh loop coupled to thesupporting trunk and configured to loop around the person's thigh. Theantimoving support can include at least a thigh loop coupled to a thighlink and configured to loop around the person's thigh. The antimovingsupport can include at least a thigh loop coupled to a frame andconfigured to loop around the person's thigh.

In an implementation, a trunk supporting exoskeleton configured to beworn by a person to reduce the muscle forces in the wearer's back duringforward lumbar flexion, the exoskeleton includes: a supporting trunkconfigured to support a wearer's trunk; and two thigh links configuredto couple to a wearer's thighs. The thigh links are rotatably coupled tothe supporting trunk in a manner that allows for flexion and extensionof thigh links relative to the supporting trunk. A belt is configured tocouple the person and the trunk supporting exoskeleton in a manner suchthat it impedes the trunk supporting exoskeleton from moving upwardlytoward the person's shoulder when the person is bending. Two torquegenerators are coupled to the supporting trunk and the thigh links. Whenthe wearer bends forward in the sagittal plane, the torque generatorsimpose a resisting torque between the supporting trunk and the thighlinks, causing the supporting trunk to impose a force against a wearer'strunk and the thigh links to impose a force onto wearer's thighs.

Other objects, features, and advantages of the present invention willbecome apparent upon consideration of the following detailed descriptionand the accompanying drawings, in which like reference designationsrepresent like features throughout the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a trunk supporting exoskeleton of the present invention ona forward leaning wearer;

FIG. 2 depicts forces imparted on the wearer of FIG. 1, with the trunksupporting exoskeleton removed for clarity;

FIG. 3 depicts a back perspective view of a trunk supportingexoskeleton;

FIG. 4 is a side view of a passive torque generator embodiment of thepresent invention in an unengaged position;

FIG. 5 is a side view of the passive torque generator of FIG. 4 in afirst engaged position;

FIG. 6 is a side view of the passive torque generator of FIG. 4 in asecond engaged position;

FIG. 7 depicts a human interface embodiment of the supporting trunk;

FIG. 8 depicts another human interface embodiment of the supportingtrunk;

FIG. 9 depicts a portion of the exoskeleton embodiment with abductionand adduction capability;

FIG. 10 depicts a signal processor of the present invention;

FIG. 11 depicts a first method of control of the present invention;

FIG. 12 depicts an alternative method of control of the presentinvention; and

FIG. 13 depicts another human interface embodiment of the supportingtrunk.

FIG. 14 depicts an embodiment of the trunk supporting exoskeleton.

FIG. 15 depicts an embodiment of torque generator;

FIGS. 16A-16B depict an embodiment of torque generator;

FIGS. 17A-17B depict an embodiment of torque generator;

FIG. 18 depicts an embodiment of torque generator with a locking system;

FIG. 19 depicts an embodiment of torque generator with a locking system;

FIG. 20 depicts an embodiment of torque generator with a locking system;

FIG. 21 depicts an embodiment of a trunk supporting exoskeleton.

FIG. 22 depicts reaction forces from user onto trunk supportingexoskeleton.

FIG. 23 depicts the addition of reaction forces.

FIG. 24 depicts reaction forces from user onto trunk supportingexoskeleton.

FIG. 25 depicts the addition of reaction forces.

FIG. 26 depicts an embodiment of antimovement support

FIG. 27 depicts an embodiment of antimovement support.

FIG. 28 depicts an embodiment of a trunk supporting exoskeleton.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a trunk supporting exoskeleton 100 (referred to asexoskeleton 100) which is configured to be worn by a person or wearer.Exoskeleton 100, in addition to other functions, reduces the muscleforces in the wearer's back during forward lumbar flexion. In general,exoskeleton 100 comprises: two thigh links 104 and 106, which areconfigured to couple to a wearer's thighs 108 and 110; and a supportingtrunk 112, which is configured to be coupled to the person's trunk 114.Supporting trunk 112 is rotatably coupled to thigh links 104 and 106,allowing for the flexion and extension along arrows 105 and 107 of thighlinks 104 and 106 with respect to supporting trunk 112. Additionally,exoskeleton 100 includes first and second opposing torque generators 116(only one of which is depicted in FIG. 1), capable of creating torquesbetween supporting trunk 112 and respective first and second thigh links104 and 106.

In operation, when a wearer bends forward in the sagittal plane suchthat supporting trunk 112 deviates beyond a straight line 120, at leastone of torque generators 116 imposes a resisting torque betweensupporting trunk 112 and its corresponding thigh link 104 and 106. Morespecifically, line 120 extends at a predetermined angle from a straightvertical line 121, and represents a point beyond which torque generatorsare actuated. In other words, during forward lumbar flexion, whensupporting trunk 112 extends beyond a predetermined angle from vertical,torque is imposed on thigh links 104 and 106. As shown in FIG. 2, thisdevice causes supporting trunk 112 to impose a force 122 onto a person'strunk 114, and thigh links 104 and 106 to impose forces 124 and 126 ontothe wearer's respective thighs 108 and 110. It should be understood thatexoskeleton 100 could be configured such that torque is imposed on thighlinks 104 and 106 when a predetermined portion of supporting trunk 112extends beyond a predetermined angle from vertical. In some embodimentof the invention, torque may be imposed when any portion of supportingtrunk 112 extends beyond line 120. In general, exoskeleton 100 can beconfigured such that torque is imposed on thigh links 104 and 106 whensupporting trunk 112 shapes itself into a generally bent configuration.

Further, in operation, when supporting trunk 112 is not deviated fromline 120, torque generators 116 impose no resisting torques betweensupporting trunk 112 and thigh links 104 and 106 during the entire rangeof motion of thigh links 104 and 106. This is a unique characteristic ofthis device where the person can walk, run, and sit without anyconstraint as long as the person's trunk is substantially verticallyaligned (i.e. not bent or not deviated beyond line 120). Torquegenerators 116 have unique characteristics where they only provideresisting torque when the human trunk is bent more than a predeterminedvalue of an angle A, regardless of the human thighs' angles with respectto the person's trunk 114. As long as the person's trunk does not extendbeyond line 120, regardless of the person legs positions and posture, notorque is generated by the torque generators 116. FIG. 3 is aperspective view of the invention where the flexion and extension ofthigh link 104 with respect to supporting trunk 112 along axis 109 isdepicted clearly.

FIG. 4 describes an embodiment of torque generators 116 where respectivecovers have been removed. It should be noted that torque generators 116are identical to each other and therefore, only the torque generatorshown in FIG. 4 will be discussed in detail. As shown, torque generator116 comprises: an upper bracket 130 coupled to supporting trunk 112; alower bracket 132 coupled to thigh link 104 and rotatably coupled in asagittal plane to upper bracket 130; a resilient pendulum 134 which isrotatably mounted on upper bracket 130; and an engagement bracket 136which is securely coupled onto lower bracket 132. In operation, when apredetermined portion of upper bracket 130 extends past line 120, asdepicted in FIG. 5, resilient pendulum 134 comes into contact withengagement bracket 136, causing a resisting torque between upper bracket130 and lower bracket 132. When upper bracket 130 is not deviated fromline 120, as depicted in FIG. 4, resilient pendulum 134 will not be incontact with engagement bracket 136, and no resisting torque is producedbetween upper bracket 130 and lower bracket 132. In some embodiments ofthe invention, resilient pendulum 134 behaves like a compression springwhere deflections result in compression forces. In some embodiments ofthe invention, engagement bracket 136 and lower bracket 132 are aone-piece part.

FIG. 6 shows a situation where a person has bent at the waistsubstantially and resilient pendulum 134 is compressed, such that thelength is shortened substantially. In some embodiments of the inventionas shown in FIG. 4, FIG. 5 and FIG. 6, resilient pendulum 134 comprisesan air spring comprising cylinder 204 and piston 209 moving relative toeach other. In some embodiments of the invention, resilient pendulum 134is a coil spring. Engagement bracket 136 has a profile that does notallow the tip of resilient pendulum 134 to slide relative to engagementbracket 136. In the embodiment of the invention depicted, engagementbracket 136 has a profile that matches the circular profile of the tipof the resilient pendulum 134. More specifically, engagement bracket 136includes a scalloped upper wall 200 including a plurality of curveddivots 202 separated by peaks 203. Resilient pendulum 134 furtherincludes a tip 210 in the form of a round knob sized to fit within eachof curved divots 202. As depicted in FIG. 5, when a wearer bends beyonda predetermined point represented by line 120, tip 210 engages with oneof curved divots 202 and is held in position by peaks 203, such that,upon further bending of the wearer, resilient pendulum 134 will be heldin place and the resilient pendulum 134 will compress. In someembodiments of the invention, scalloped upper wall 200 or tip 210, orboth, may include a frictional surface to prevent the sliding motion oftip 210 within a curved divot 202.

In some embodiments of the invention, torque generators 116 are activesystems. Examples of active torque generators which can be utilized withthe present invention include, without limitation, hydraulic motors,pneumatic motors, and electric motors, including, without limitation,alternating current (AC) motors, brush-type direct current (DC) motors,brushless DC motors, electronically commutated motors (ECMs), steppingmotors, and combinations thereof. In some embodiments of the invention,torque generators 116 each include an electric motor and a transmission.The resistance supplied by first and second torque generators 116between supporting trunk 112 and respective thigh links 104 and 106impose a force onto the person's trunk 114 in the manner depicted inFIG. 1. These torques also cause thigh links 104 and 106 to imposeforces onto the wearer's thighs 108 and 110.

The manner in which the resistance torque can be automatically adjustedwhen an active torque generator is used will now be discussed withreference to FIGS. 10-12. In some embodiments of the invention, as shownin FIG. 10, exoskeleton 100 includes a signal processor 240 configuredto produce a control signal 242 for torque generators 116, whereincontrol signal 242 drives torque generators 116. Signal processor 240incorporates a controller 252 that produces control signal 242 fortorque generators 116 as a function of a set of input signals thatsignal processor 240 receives. Examples of input signals that signalprocessor 240 receives include, without limitation, signals representingangles of thigh links 104 and 106 with respect to supporting trunk 112,signals representing the velocity of supporting trunk 112 with respectto thigh links 104 and 106, signals representing the acceleration ofsupporting trunk 112 with respect to thigh links 104 or 106, a signalrepresenting the absolute angle of supporting trunk 112, a signalrepresenting the absolute velocity of supporting trunk 112, a signalrepresenting the absolute acceleration of supporting trunk 112, a signalrepresenting at least one torque generator's movement, a signalrepresenting at least one torque generator's speed, a signalrepresenting at least one torque generator's acceleration, a signalrepresenting at least one torque generator's torque, a signalrepresenting at least one torque generator's force, a signalrepresenting the person's movement, a signal representing the person'sbending angle, a signal representing the person's bending velocity, asignal representing the person's bending acceleration, a signalrepresenting the contact force between person 102 and supporting trunk112, a signal representing an electromyography (EMG) signal from theperson and combinations thereof.

Various sensors can be utilized to provide controller 252 with thenecessary signal information. In one preferred embodiment depicted inFIG. 11, supporting trunk 112 includes a first sensor 244 generating afirst signal 246 representing an output from first sensor 244. In afirst example, first sensor 244 is an absolute angle sensor and firstsignal 246 is an absolute angle signal representing the angle thatperson 102 or supporting trunk 112 has bent forward relative to line 120or vertical line 121 (shown in FIG. 1). However, it should be understoodthat first sensor 244 could be a velocity sensor, an accelerometer, orother type of movement sensor. Supporting trunk 112 can also include asecond sensor 248 (shown in FIG. 11) generating a second signal 250representing an output from second sensor 248. In one example, secondsensor 248 is an angle sensor and second signal 250 is an angle signalrepresenting the angle of supporting trunk 112 with respect to thighlinks 104 or 106. In general, second sensor 248 is either included inthe torque generators 116, installed on the same location on thigh links104 or 106, or supporting trunk 112 that torque generator 116 areinstalled. However, it should also be understood that second sensor 248could be a torque generator movement sensor, a torque generator speedsensor, a torque generator accelerometer, a torque generator torque orforce sensor, or any type of standard movement sensor. In operation, asshown in FIG. 11, signal processor 240 produces control signal 242 fortorque generators 116 as a function of first signal 246, or secondsignal 250, or both. That is, controller 252 utilizes first and secondsignals 246 and 250 as a feedback signal to generate control signal 242.The type of controller utilized dictates the magnitude of the resistancetorque. One can find a variety of algorithms for controller 252 toperform the indicated task. In general, controllers with large gainslead to large resistance torques, while controllers with small gainsresult in smaller resistance torque.

As shown in FIG. 12, exoskeleton 100 may also include a force orpressure sensor 260 generating a force or pressure signal 262representing the force or pressure between person 102 and supportingtrunk 112. In operation, signal processor 240 produces control signal242 for torque generators 116 as a function of force or pressure signal262. That is, controller 252 utilizes force or pressure signal 262 as afeedback signal to generate control signal 242.

From the discussion above, it should be understood that controller 252could be programmed and configured to activate torque generators 116 ina variety of ways based on signals 246, 250, or 262, or any combinationthese, from sensors 244, 248, or 260, or any combination of these. Insome embodiments of the invention, the resistance torque is a functionof how much person 102 is bending forward. For example, in someembodiments of the invention, the resistance torque increases as person102 bends forward. In some embodiments of the invention, the resistancetorque is a function of the angle between person 102 and a line 120. Insome embodiments of the invention, the resistance torque increaseslinearly as the angle between person 102 and vertical line 121 (shown inFIG. 2) increases. In some embodiments of the invention, the resistancetorque is a function of how much supporting trunk 112 moves toward thighlinks 104 or 106. In some embodiments of the invention, the resistancetorque is a function of the angle between supporting trunk 112 andvertical line 121. In some embodiments of the invention, the resistancetorque increases linearly as the angle between supporting trunk 112 andvertical line 121 increases. In some embodiments of the invention, thecontroller is configured to adjust the resistance torque imposed by thefirst and second torque generators to be generally constant for at leastone segment of a bending movement of a wearer.

In some embodiments of the invention, as shown in FIG. 1 and FIG. 3,supporting trunk 112 comprises a human interface 142, which isconfigured to be coupled to a person's trunk 114, and a frame 140, whichis configured to be coupled to human interface 142. Frame 140 isrotatably coupled to thigh links 104 and 106 allowing for extension andflexion of thigh links 104 and 106 relative to frame 140. Frame 140comprises any material or combination of materials capable of performingthe indicated functions. Examples of materials of frame 140 include,without limitation, aluminum materials, plastic materials, carbon fibermaterials, metallic materials, and combinations thereof. In someembodiments of the inventions, frame 140 comprises of plurality ofcomponents coupled or hinged to each other. From the discussion above,it should be understood that controller 252 could be programmed andconfigured to activate torque generators 116 in a variety of ways basedon signals 246, 250, or 262, or any combination of these from sensors244, 248, or 260, or any combination of these. In some embodiments ofthe invention, the resistance torque is a function of how much person102 is bending forward. For example, in some embodiments of theinvention, the resistance torque increases as person 102 bends forward.In some embodiments of the invention, the resistance torque is afunction of the angle between person 102 and a line 120. In someembodiments of the invention, the resistance torque increases linearlyas the angle between person 102 and vertical line 121 (shown in FIG. 2)increases. In some embodiments of the invention, the resistance torqueis a function of how much supporting trunk 112 moves toward thigh links104 or 106. In some embodiments of the invention, the resistance torqueis a function of the angle between supporting trunk 112 and verticalline 121. In some embodiments of the invention, the resistance torqueincreases linearly as the angle between supporting trunk 112 andvertical line 121 increases. In some embodiments of the invention, thecontroller is configured to adjust the resistance torque imposed by thefirst and second torque generators to be generally constant for at leastone segment of a bending movement of a wearer.

In some embodiments of the invention, human interface 142 comprises aback panel 160 to interface the person's back, as depicted in FIG. 7. Insome embodiments of the invention, back panel 160 is compliant anddeforms as the person bends. In some embodiments of the invention, humaninterface 142 further comprises at least one shoulder strap 150configured to couple to the person. Referring back to the embodiment ofFIG. 1, the invention may also include a front panel 151 adapted toengage the front of a person's trunk 114, to provide additional support.Human interface 142 comprises any material or combination of materialscapable of performing the indicated functions. Examples of materials ofhuman interface 142 include, without limitation, fabric materials,plastic materials, belts, leather materials, carbon fiber materials,metallic materials, and combinations thereof.

In some embodiments of the invention, as shown in FIG. 7, humaninterface 142 is slide-able along axis 144 with respect to frame 140(i.e. slide-able along a length of frame 140). This sliding movement,shown by arrow 146, facilitates the bending maneuver of the wearer.

In some embodiments of the invention, as shown in FIG. 7, humaninterface 142 is rotatable around axis 144 with respect to frame 140.Arrow 148 shows this rotational movement. This rotation allows theperson to twist his/her upper body without moving the person's legs.

In some embodiments of the invention, as shown in FIG. 8, humaninterface 142 is rotatable around axis 170 with respect to frame 140.Arrow 172 shows this rotational movement. This rotation facilitates thebending maneuver of the person.

In some embodiments of the invention, as shown in FIG. 13, humaninterface 142 is rotatable around axis 220 with respect to frame 140.Arrow 222 shows this rotational movement. This rotation facilitates therotational maneuver of the person.

In some embodiment of the invention, thigh links 104 and 106 eachfurther comprise at least one thigh strap 180 and 182 configured tocouple to wearer's thighs 108 and 110, as depicted in Figures. Thighstraps 180 and 182 comprise any material or combination of materialscapable of performing the indicated functions. Examples of materials ofthigh straps 180 and 182 include, without limitation, fabric materials,plastic materials, belts, leather materials, carbon fiber materials,metallic materials, and combinations thereof.

In some embodiments of invention, as shown in FIG. 9, frame 140 furthercomprises two rotary abduction-adduction joints 190 and 192 allowing forabduction and adduction of respective thigh links 104 and 106 relativeto supporting trunk 112. As shown in FIG. 9, axes 193 and 194 representthe axes of abduction and adduction joints. FIG. 9 shows a portion ofsupporting trunk 112 where thigh link 104 has abducted.

Although described with reference to preferred embodiments of theinvention, it should be readily understood that various changes,modifications, or both could be made to the invention without departingfrom the spirit thereof. For instance, the various human interfaces,thigh straps, and torque generators can be combined in various ways toform different overall embodiments of the present invention. In general,the invention is only intended to be limited by the scope of thefollowing claims.

An ordinary person skilled in the art would understand that there areseveral manufacturing methods for construction of upper bracket 130 andframe 140. One can fabricate upper bracket 130 separately and thencouple it to frame 140 either by fasteners, through welding or othercommon engineering coupling methods. Although, FIGS. 4 and 5 show thatupper bracket 130 is coupled to frame 140, one can manufacture frame 140or supporting trunk 112 to include upper bracket 130 as one piece.Additionally although FIGS. 4 and 5 show that engagement bracket 136 issecurely coupled onto lower bracket 132, one can manufacture these twoparts as one piece. Although FIGS. 4 and 5 show that lower bracket 132is securely coupled onto thigh link 104, one can manufacture these twoparts as one piece.

FIG. 14 illustrates another embodiment of trunk supporting exoskeleton300, which is configured to be worn by a person or wearer. The person isnot shown in FIG. 14; however, exoskeleton 300 is worn like exoskeleton100 as shown in FIGS. 1, 3 and 4. Trunk supporting exoskeleton 300reduces the muscle forces in the wearer's back during forward lumbarflexion, in addition to other functions. In general, trunk supportingexoskeleton 300 comprises two thigh links 104 and 106, which areconfigured to be coupled to a wearer's thighs; and a supporting trunk112, which is configured to be coupled to the person's trunk 114.Supporting trunk 112 is rotatably coupled to thigh links 104 and 106,allowing for the flexion and extension along arrows 105 and 107 of thighlinks 104 and 106 with respect to supporting trunk 112. Additionally,trunk supporting exoskeleton 300 includes first and second opposingtorque generators 116 and 118 capable of creating torques betweensupporting trunk 112 and respective first and second thigh links 104 and106. It should be understood that the flexion and extension along arrows105 and 107 of thigh links 104 and 106 with respect to supporting trunk112 take place at the same location that human legs rotate relative tothe human trunk. This colocation of axes allows little or no slidingmotion between the trunk supporting exoskeleton components and thewearer. If the axes of rotation of thigh links 104 and 106 relative tosupporting trunk 112 are not co-located with the human leg flexion andextension axes, then the supporting trunk 112 and thigh links 104 and106 may slide relative to human trunk and human legs during flexion andextension.

As shown previously, supporting trunk 112 comprises a human interface142, which is configured to be coupled to a person's trunk 114, and aframe 140, which is configured to be coupled to human interface 142.Frame 140 is rotatably coupled to thigh links 104 and 106 allowing forextension and flexion of thigh links 104 and 106 relative to frame 140.Frame 140 comprises any material or combination of materials capable ofperforming the indicated functions. In some embodiments of theinventions as shown in FIG. 14, frame 140 comprises of a waist frame 312and a spine frame 304 rotatably coupled to each other. Axis 306represents the rotation axis of spine frame 304 relative to waist frame312. Arrows 308 and 310 show the directions of movements of spine frame304 relative to waist frame 312. In some embodiments of the invention,waist frame 312 is substantially parallel with the person's hip line. Insome embodiments of the invention, spine frame 304 is substantiallyparallel with the user's spine.

In some embodiments of the invention, as shown in FIG. 21, frame 140comprises at least one resilient element 313 that resists the rotationof spine frame 304 relative to waist frame 312. The force or moment ofresilient element 313 causes spine frame 304 and waist frame 312 toremain orthogonal to each other. Resilient element 313 comprises anydevice or combination of devices capable of performing the indicatedfunctions. Examples of resilient element 313 include, withoutlimitation, gas spring, air spring, leaf spring, torsional springcompression spring, linear spring, tensile spring, and combinationsthereof.

In some embodiments of the invention, as shown in FIG. 14, frame 140further comprises two rotary abduction-adduction joints 190 and 192allowing for abduction and adduction of respective thigh links 104 and106 relative to supporting trunk 112. As shown in FIG. 14, axes 193 and194 represent the axes of abduction and adduction joints. In someembodiments of invention, as shown in FIG. 14, thigh links 104 and 106further comprise two other rotary joints 314 and 316 allowing forrotation of respective thigh links 104 and 106 relative to lower bracket132. As shown in FIG. 14, axes 302 and 318 represent the axes ofrotations of thigh links 104 and 106 relative to lower bracket 132.Although FIG. 14 depicts that axes 302 and 318 are all parallel withaxes 193 and 194, an ordinary skilled in the art would understand thatin general the orientations of axes 302 and 318 relative to axes 193 and194 depend on the flexion and extension of thigh links 104 and 106.

In some embodiments of the invention, resilient pendulum 134 isrotatably coupled to upper bracket 130 from its end as shown in FIGS. 4and 5. In some other embodiments of the invention as shown in FIG. 15and FIGS. 16A-16B resilient pendulum 134 is rotatably coupled to upperbracket 130 such that the location of the rotating point 320 ofresilient pendulum 134 relative to upper bracket 130 is adjustable.FIGS. 16A-16B show an embodiment of the invention where a holding block322 is rotatably coupled to upper bracket 130. Axis 328 (shown in FIG.15) shows the axis of rotation of holding block 322 relative to upperbracket 130. Rotating point 320 represents the rotating point of holdingblock 322 relative to upper bracket 130. Resilient pendulum 134 issecured to holding block 322. In this embodiment of the invention, thelocation of rotating point 320 of resilient pendulum 134 can be adjustedrelative to holding block 322. FIG. 16 shows two configurations oftorque generator 116 where the position of resilient pendulum 134 hasbeen adjusted. The figure on the right shows the case where resilientpendulum 134 is lowered as much as a distance D represented by 326. Thisadjustment allows for exoskeleton sensitivity as to what torso angleresilient pendulum 134 would get engaged with engagement bracket 136.

Resilient pendulum 134 comprises any device or combination of devicescapable of performing the indicated functions. Examples of resilientpendulum 134 include, without limitation, gas spring, air spring, leafspring, torsional spring, compression spring, linear spring, tensilespring, and combinations thereof. In some embodiments of the inventionas shown in FIGS. 17A-17B, a mass 330 is coupled to resilient pendulum134. The location of mass 330 can be adjusted relative to resilientpendulum 134 to allow for desired natural frequency of resilientpendulum 134.

In some embodiments of the invention, torque generator 116 furthercomprises a locking system 400 to prevent the rotational motion ofresilient pendulum 134 relative to upper bracket 130. In operation whenthe rotational motion of resilient pendulum 134 relative to upperbracket 130 is prevented, then resilient pendulum 134 moves in unisonwith upper racket 130 and resilient pendulum 134 will not be in contactwith engagement bracket 136. This means no resisting torque is producedbetween upper bracket 130 and lower bracket 132. When the rotationalmotion of resilient pendulum 134 relative to upper bracket 130 is notprevented, then resilient pendulum 134 may contact engagement bracket136 when the person bends and a torque is produced between upper bracket130 and lower bracket 132.

FIGS. 18 and 19 show exploded views of an embodiment of locking system400 from two different views. Locking system 400, among othercomponents, comprises a cover bracket 402 coupled to upper bracket 130and a moving bracket 404 capable of moving relative to cover bracket 402along arrows 406 and 408. Moving bracket 404 further comprises at leastone protrusion 410. This protrusion 410 can be made in a variety ofshapes and geometry. In the embodiment shown in 19, protrusion 410 has atriangular shape. In the embodiment shown in FIGS. 18 and 19, resilientpendulum 134 or holding block 322 further includes two pendulumprotrusions 412 and 414. In operation when moving bracket 404 is in itsunlocked position (pushed up as shown in FIG. 19), protrusion 410 willnot be in between pendulum protrusions 412 and 414 and will not preventthe motion of resilient pendulum 134 with respect to moving bracket 404.When moving bracket 404 is in its locked position (pushed down) as shownin FIG. 20, protrusion 410 moves in between pendulum protrusions 412 and414 preventing the motion of resilient pendulum 134 with respect tomoving bracket 404. In general, moving bracket 414 has at least twopositions. When moving bracket 414 is in its first position, protrusion410 will not prevent the motion of resilient pendulum 134 with respectto moving bracket 414 and when moving bracket 414 is in its secondposition, protrusion 410 will interfere the rotation of resilientpendulum 134 and will prevent the motion of resilient pendulum 134 withrespect to moving bracket 414.

As shown in FIG. 2, this device causes supporting trunk 112 to impose aforce 122 onto a person's trunk 114, and thigh links 104 and 106 toimpose forces 124 and 126 onto the wearer's respective thighs 108 and110. As shown in FIG. 22 the reaction forces from user onto trunksupporting exoskeleton 300 are presented by 340, 342, and 344. In thequasi-static case, reaction forces 340, 342, and 344 are equal but inopposite directions to forces 122, 124, and 126. The addition ofreaction forces 340, 342, and 344 results in a resultant force 346 ontrunk supporting exoskeleton 300. Resultant force 346 changes itsdirection as a function of the person's posture. FIG. 23 shows resultantforce 346 which is from left to right and slightly downwardly since theperson has not squatted substantially. FIG. 24 shows another user'sposture where the user has squatted deeper. As shown in FIG. 25, theresultant force 346 is from left to right and slightly upwardly. Thisindicates that trunk supporting exoskeleton 300 seeks to move toward theperson (generally from the left to the right and slightly upwardly asshown in FIG. 25) and contact the person from back for equilibrium. Itis best to ensure that the trunk supporting exoskeleton 300 contacts theperson from the back in an ergonomic way. It is preferable that theforce imposed on the user from trunk supporting exoskeleton 300 isimposed by soft components (made of fabric) rather than the hardcomponents such as waist frame 312 and spine frame 304. It is thereforenecessary that these soft components are secured to both the trunksupporting exoskeleton 300 and the user so the trunk supportingexoskeleton 300 does not move upwardly on the user. Additionally, it ispreferable that the force from trunk supporting exoskeleton 300 isimposed on the proper location on the person and is distributed evenlyon a large area on the person. To ensure the above condition, we suggestan antimoving support 350, which is configured to couple trunksupporting exoskeleton 300. Antimoving support 350 impedes the trunksupporting exoskeleton 300 from moving upwardly toward the person'sshoulder when person 102 is squatting.

In some embodiments of the invention as shown in FIG. 26, antimovingsupport 350 is a belt 352, which is configured to contact to person'ship area and to couple supporting trunk 112 at locations close to therotation points of thigh links 104 and 106 relative to supporting trunk112. As shown in FIG. 26, antimoving support 350 is coupled to waistframe 312 through a connecting loop 358. The length of belt 352 shouldbe smaller than the length of frame 140 ensure that frame 140 will notcome in contact with the wearer and the force imposed by the device onthe user from the back is actually imposed by belt 352 and not by frame140. In some embodiments of the invention as shown in FIG. 27,antimoving support 350 comprises a seat support 354, which is configuredto contact the person's hip and buttock areas and to couple supportingtrunk 112. As shown in FIG. 26, antimoving support 350 is coupled towaist frame 312 through a connecting loop 358 and connecting belt 360.In some embodiments, invention antimoving support 350 further comprisesat least a thigh loop 356 configured to loop around the person's thigh.As shown in FIG. 27, thigh loop 356 is coupled to seat support 354. Thedevice of claim 15 wherein antimoving support 350 comprises at least athigh loop 356 which is coupled to a frame 140 and configured to looparound the person's thighs.

In some embodiments of the invention, human interface 142 comprises aback panel 160 to interface the person's back, as depicted in FIG. 7. Insome embodiments of the invention, human interface 142 further comprisesat least one shoulder strap 150 configured to couple to the person. Insome embodiments of the invention as shown in FIG. 28, human interface142 comprises a back panel configured to interface with a wearer's backand a pair of shoulder straps configured to be coupled to back panel 160and frame 140.

This description of the invention has been presented for the purposes ofillustration and description. It is not intended to be exhaustive or tolimit the invention to the precise form described, and manymodifications and variations are possible in light of the teachingabove. The embodiments were chosen and described in order to bestexplain the principles of the invention and its practical applications.This description will enable others skilled in the art to best utilizeand practice the invention in various embodiments and with variousmodifications as are suited to a particular use. The scope of theinvention is defined by the following claims.

The invention claimed is:
 1. A trunk supporting exoskeleton configuredto be worn by a person to reduce the muscle forces in the wearer's backduring forward lumbar flexion, the exoskeleton comprising: a supportingtrunk comprising a seat harness configured to contact the person'sbuttock area; two thigh links configured to couple to a wearer's thighs,the thigh links are rotatably coupled to the supporting trunk in amanner that allows for flexion and extension of thigh links relative tothe supporting trunk along human hip flexion and extension axes, whereinthe supporting trunk is coupled at locations close to the rotationpoints of thigh links relative to seat harness in a manner such thatforward rotation of the supporting trunk from a vertical line does notcause substantial motion for the seat harness; and two torquegenerators, wherein a first torque generator of the two torquegenerators is coupled between the supporting trunk and a first thighlink of the two thigh links, and a second torque generator of the twotorque generators is coupled between the supporting trunk and a secondthigh link of the two thigh links, and when the wearer bends forward inthe sagittal plane, the torque generators impose a resisting torquebetween the supporting trunk and the thigh links, causing the supportingtrunk to impose a force against a wearer's trunk and the thigh links toimpose a force onto wearer's thighs.
 2. The trunk supporting exoskeletonof claim 1 wherein at least one of the first and second torquegenerators comprises: an upper bracket configured to be coupled to thesupporting trunk; a lower bracket configured to be coupled to one of thefirst and second thigh links and rotatably coupled to the upper bracket;a resilient pendulum rotatably coupled to the upper bracket; and anengagement bracket coupled to the lower bracket, wherein when apredetermined portion of the upper bracket extends beyond apredetermined angle from vertical, the resilient pendulum comes intocontact with the engagement bracket, causing a resisting torque betweenthe upper bracket and the lower bracket, and when the predeterminedportion of the upper bracket does not extend beyond a predeterminedangle from vertical, the resilient pendulum is not in contact with theengagement bracket, and does not impose resisting torque between theupper bracket and the lower bracket.
 3. The trunk supporting exoskeletonof claim 2 wherein the upper bracket is manufactured as a part of thesupporting trunk.
 4. The trunk supporting exoskeleton of claim 2 whereinthe lower bracket is manufactured as a part of the thigh link.
 5. Thetrunk supporting exoskeleton of claim 2 wherein the thigh link isadjustable for various lengths.
 6. The trunk supporting exoskeleton ofclaim 2 wherein the engagement bracket is manufactured as a part of thelower bracket.
 7. The trunk supporting exoskeleton of claim 2 whereinthe resilient pendulum is rotatably coupled to the upper bracket wherethe rotating point location of the resilient pendulum relative to theupper bracket is adjustable.
 8. The trunk supporting exoskeleton ofclaim 2 wherein a holding block is rotatably coupled to the upperbracket and the resilient pendulum is secured to the holding block. 9.The trunk supporting exoskeleton of claim 2 wherein a mass is coupled tothe resilient pendulum and its location relative to the resilientpendulum can be adjusted to produce various natural oscillationfrequencies.
 10. The trunk supporting exoskeleton of claim 2 wherein theresilient element comprises an element or combination of elementsselected from a group consisting of gas spring, air spring, leaf spring,torsional spring, compression spring, linear spring and tensile spring.11. The trunk supporting exoskeleton of claim 2 wherein the torquegenerator further comprises a locking system to prevent the rotationalmotion of the resilient pendulum relative to the upper bracket.
 12. Thetrunk supporting exoskeleton of claim 11 wherein the locking system,among other things, comprises a cover bracket coupled to the upperbracket and a moving bracket capable of moving relative to the coverbracket wherein when the moving bracket is in its unlocked position, itwill not prevent the resilient pendulum from rotating relative to theupper bracket and when the moving bracket is in its locked position, themoving bracket prevents the resilient pendulum from rotating relative tothe upper bracket.
 13. The trunk supporting exoskeleton of claim 12wherein the moving bracket, among other components, comprises aprotrusion wherein when the moving bracket is in its first position, theprotrusion will not prevent the motion of resilient pendulum withrespect to the moving bracket and when the moving bracket is in itssecond position, the protrusion will interfere the rotation of theresilient pendulum and prevent the motion of resilient pendulum withrespect to the moving bracket.
 14. A trunk supporting exoskeletonconfigured to be worn by a person to reduce the muscle forces in thewearer's back during forward lumbar flexion, the exoskeleton comprising:a supporting trunk configured to support a wearer's chest; first andsecond thigh links configured to couple to a wearer's thighs, whereineach of the first and second thigh links is rotatably coupled to thesupporting trunk in a manner that allows for flexion and extension ofrespective first and second thigh links relative to the supportingtrunk; an antimoving support, coupled to the supporting trunk,configured to couple the person and the trunk supporting exoskeleton ina manner such that it impedes the trunk supporting exoskeleton frommoving upwardly toward the person's shoulder when the person is bending;and first and second torque generators, wherein each of the first andsecond torque generators is configured to generate torque between therespective first and second thigh links and the supporting trunk,wherein when a wearer bends forward in the sagittal plane such that apredetermined portion of the supporting trunk extends beyond apredetermined angle from vertical, at least one of the first or secondtorque generators imposes a resisting torque between the supportingtrunk and at least one of the first and second thigh links, causing thesupporting trunk to impose a force against a wearer's trunk and at leastone of the first and second thigh links to impose a force onto awearer's thigh.
 15. The trunk supporting exoskeleton of claim 14 whereinthe antimoving support is a belt configured to couple the person hiparea and to couple the supporting trunk at locations close to therotation points of thigh links relative to supporting trunk in a mannersuch that forward rotation of the supporting trunk from a vertical linedoes not cause substantial motion for the seat harness.
 16. The trunksupporting exoskeleton of claim 14 wherein the antimoving support is aseat harness configured to contact the person's buttock area and tocouple the supporting trunk at locations close to the rotation points ofthigh links relative to supporting trunk in a manner such that forwardrotation of the supporting trunk from a vertical line does not causesubstantial motion for the seat harness.
 17. A trunk supportingexoskeleton configured to be worn by a person to reduce the muscleforces in the wearer's back during forward lumbar flexion, theexoskeleton comprising: a supporting trunk configured to contact awearer's trunk; two thigh links configured to couple to a wearer'sthighs, the thigh links are rotatably coupled to the supporting trunk ina manner that allows for flexion and extension of thigh links relativeto the supporting trunk along human hip flexion and extension axes; andtwo torque generators, wherein a first torque generator of the twotorque generators is coupled between the supporting trunk and a firstthigh link of the two thigh links, and a second torque generator of thetwo torque generators is coupled between the supporting trunk and asecond thigh link of the two thigh links, when the wearer bends forwardin the sagittal plane, the torque generators impose a resisting torquebetween the supporting trunk and the thigh links, causing the supportingtrunk to impose a force against a wearer's trunk and the thigh links toimpose a force onto wearer's thighs, and at least one of the first orsecond torque generators comprises: an upper bracket configured to becoupled to the supporting trunk; a lower bracket configured to becoupled to one of the first and second thigh links and rotatably coupledto the upper bracket.
 18. The trunk supporting exoskeleton of claim 17comprising: a resilient pendulum rotatably coupled to the upper bracket,wherein the torque generator comprises a locking system to prevent therotational motion of the resilient pendulum relative to the upperbracket; and an engagement bracket coupled to the lower bracket.
 19. Thetrunk supporting exoskeleton of claim 18 wherein when a predeterminedportion of the upper bracket extends beyond a predetermined angle fromvertical, the resilient pendulum comes into contact with the engagementbracket, causing a resisting torque between the upper bracket and thelower bracket.
 20. The trunk supporting exoskeleton of claim 18 whereinwhen the predetermined portion of the upper bracket does not extendbeyond a predetermined angle from vertical, the resilient pendulum isnot in contact with the engagement bracket, and does not imposeresisting torque between the upper bracket and the lower bracket.